1. Field of the Invention
This invention relates, in general, to guides for saws and, more particularly, to lumber mill apparatus for use with chain saws.
2. Description of the Prior Art
With the increased use and sales of chain saws has come the desire to use the chain saw for the cutting of logs into lumber useable for building material. A number of devices have been invented to this end as best typified by U.S. Pat. Nos. 4,146,962; 3,965,788; 3,092,156; and 3,051,203.
To obtain planar cuts and cuts of standard dimensions it is essential that the log being cut be rendered immovable; that the chain saw be drawn smoothly through the log without lateral pressure; and that the chain saw be moved without deviation relative to the guide member. Additionally, it is highly desirable that the saw bar be placed at an efficient cutting angle relative to the log and that the process not be time consuming. It is also important that the chain saw be readily removable from the guide apparatus for conventional cutting purposes.
Prior art devices, for the most part, are simply not adequate to provide the precision cutting which is required for building materials. Guide members in the existing art must be generally reset on the log after each slab is cut. Additionally, the guides must themselves be straight requiring a flat surface to begin the procedure. Such surfaces are ordinarily provided by a plank being nailed directly to the log. This, in itself, is laborious and time consuming and often is not at all practical due to the natural cylindrical shape of the log. For this reason, an initial cut is often made in the log to make the supporting surface for the guide member as planar as possible. Besides log waste, such attempts are particularly frustrating and often unsuccessful. The overwhelming defect in prior art devices, however, is the necessity of controlling the saw itself by the hand. In pulling the saw bar through the log during the cutting procedure of the chain saw, the bar invariably wavers from side to side because of the vibration of the saw and the inability of the operator to control such movement. The log acts as a fulcrum in its contact with the cutting edge on the saw bar and the chain saw, from handle to end of cutting bar, is akin to a lever. A slight movement from the plane close to the fulcrum causes an aggravated movement from the plane toward the tip of the cutting bar.